All Creatures was a series based on the semi-autobiographical novels of veterinarian James Herriot, the pseudonym of Alf Wight, MRCVS, OBE. The novels depicted a number of adventures in the life of Wight and his partners, who were fictionally called Siegfried and Tristan Farnon. Set in and around Darrowby, it dramatised the trials of a British country veterinary practice before and after World War II. It ran from 1978 to 1980, enjoyed two Christmas specials in the early 1980s and returned for four full seasons from 1988 to 1990.

The leading role was taken by an unknown actor, Christopher Timothy. Siegfried Farnon was played by Robert Hardy — widely known in the 21st century for being Cornelius Fudge in the Harry Potter movies. Tristan was played by Peter Davison, who became a household name largely as the result of Timothy's near-fatal car crash during the filming of the first series. Timothy's extended absence from the set greatly expanded the role of Tristan and transformed Davison from a recurring guest star into a co-star. Several actors recognisable from appearances in Doctor Who were later seen in All Creatures, such as Nicholas Courtney, Patrick Troughton and Lynda Bellingham.

An important role in the behind-the-scenes team of the first three seasons was played by John Nathan-Turner. He was the show's first production unit manager and worked on the series at the same time he was working in the same capacity on Doctor Who. He relinquished his job on All Creatures around the middle of the third season, largely because he had accepted the job of being Doctor Who's producer. JNT's experiences working with Davison led to his decision to offer him the role of the Fifth Doctor to succeed the departing Tom Baker.

Because of its many connections with the series, All Creatures has been popular with fans of Doctor Who. This is especially true of North American fans, as both series were widely syndicated together on PBS stations during the 1980s. Moreover, the show was co-produced by the American Arts & Entertainment Network and formed a part of that network's programming.